脉冲激发三能级体系半导体量子点的单光子发射效率

研究了脉冲激发下单个半导体量子点中单光子发射的统计特性.在旋转波近似条件下，由系统粒子数演化主方程并结合量子回归理论推导了二阶相关函数的运动方程，利用此方程讨论了二阶相关函数随输入脉冲面积的关系.在窄脉冲宽度的脉冲激发下，单光子的发射概率p和效率η都随着强度的增强而产生振荡.研究表明，采用窄脉冲宽度，当输入脉冲面积在π附近时可以得到较高的单光子发射效率. 关键词： 半导体量子点 单光子发射 三能级系统

Efficiency of single photon emission in three-level system of semiconductor quantum dots with pulsed excitation

The statistic characteristics of single photon emission in single semiconductor quantum dot with pulse excitation have been investigated.With rotating-wave approximation,we deduce the dynamics equations including second-order correlation function from the master equations of the populations and discuss the correlation function of photon emission from the exciton combination under different input pulse areas.There will appear an apparant split peak around zero time delay under strong excitation.For short pulse width,the probability of single photon emission p and the efficiency of single photon emission η oscillate as the excitation intensity increases.It is revealed that high efficient single photon emissions can be realized in this system when excited with input pulse area about π and short pulse width.